It's the first time I've seen him sleeping in his plant. Usually he's sleeping with his chin on the heater suction cup.

I have this same silk plant (only bigger) in another tank, and that betta sleeps in his plant, too. He actually camouflages really well with it. I couldn't see him in his tank the other night...was looking everywhere, and it turned out he was right in front of me in plain sight, sleeping in the plant. lol